1. Technical Field
The present invention relates to a method and apparatus for breaking a semiconductor substrate, made by forming a photovoltaic element or other element structure on a silicon wafer or the like, along a predetermined region over which a split groove is formed, a method for breaking a solar cell utilizing the above method and apparatus, and a method for fabrication of a solar cell module.
2. Description of Related Art
It has been conventionally studied to divide a solar cell comprising a large-area semiconductor substrate into small-area solar cells and connect them as by lead wires to thereby fabricate a solar cell module.
In Japanese Patent Laid-Open Nos. 2005-236017 and 2004-31839, methods are disclosed for fabricating a solar cell by forming a split groove on a semiconductor substrate using a laser or a dicing saw and dividing the substrate utilizing the split groove. In the case where a semiconductor substrate is broken along a predetermined area over which a split groove is formed, a method is generally used wherein, while a portion of the semiconductor substrate inside a predetermined area is held in position, its portion outside the predetermined area is pressed downward so that the semiconductor substrate is broken along the split groove. In this case, breaking is achieved by simultaneously applying a pressing force to the entire portion of the semiconductor substrate outside the predetermined area. Then, a stress produced during breaking is concentrated, for example, at an edge portion of the predetermined area of the semiconductor substrate. This results in the occurrence of cracking or the like and accordingly lowers a yield rate, which has been a problem.